diff --git a/src/freedombone-app-babel b/src/freedombone-app-babel
index 4d81f900..cb670b6b 100755
--- a/src/freedombone-app-babel
+++ b/src/freedombone-app-babel
@@ -66,7 +66,7 @@ function restore_remote_babel {
 }
 
 function remove_babel {
-    if ! grep -Fxq "install_babel" $COMPLETION_FILE; then
+    if [[ $(app_is_installed babel) == "0" ]]; then
         return
     fi
 
diff --git a/src/freedombone-app-batman b/src/freedombone-app-batman
index b3f65fef..22225508 100755
--- a/src/freedombone-app-batman
+++ b/src/freedombone-app-batman
@@ -79,7 +79,7 @@ function restore_remote_batman {
 }
 
 function remove_batman {
-    if ! grep -Fxq "install_batman" $COMPLETION_FILE; then
+    if [[ $(app_is_installed batman) == "0" ]]; then
         return
     fi
 
diff --git a/src/freedombone-app-blog b/src/freedombone-app-blog
index 6c139841..9a3916b3 100755
--- a/src/freedombone-app-blog
+++ b/src/freedombone-app-blog
@@ -311,7 +311,7 @@ function restore_remote_blog {
 }
 
 function remove_blog {
-    if ! grep -Fxq "install_blog" $COMPLETION_FILE; then
+    if [[ $(app_is_installed blog) == "0" ]]; then
         return
     fi
     if [ ! -d /var/www/$FULLBLOG_DOMAIN_NAME ]; then
diff --git a/src/freedombone-app-cjdns b/src/freedombone-app-cjdns
index 02b422e9..7b12e1c0 100755
--- a/src/freedombone-app-cjdns
+++ b/src/freedombone-app-cjdns
@@ -171,7 +171,7 @@ function restore_remote_cjdns {
 }
 
 function remove_cjdns {
-    if ! grep -Fxq "install_cjdns" $COMPLETION_FILE; then
+    if [[ $(app_is_installed cjdns) == "0" ]]; then
         return
     fi
     service cjdns stop
diff --git a/src/freedombone-app-dlna b/src/freedombone-app-dlna
index c8af424c..22015d19 100755
--- a/src/freedombone-app-dlna
+++ b/src/freedombone-app-dlna
@@ -149,7 +149,7 @@ function restore_remote_dlna {
 }
 
 function remove_dlna {
-    if ! grep -Fxq "install_dlna" $COMPLETION_FILE; then
+    if [[ $(app_is_installed dlna) == "0" ]]; then
         return
     fi
     service minidlna stop
diff --git a/src/freedombone-app-emacs b/src/freedombone-app-emacs
index a3445e02..f71c2780 100755
--- a/src/freedombone-app-emacs
+++ b/src/freedombone-app-emacs
@@ -99,7 +99,7 @@ function restore_remote_emacs {
 }
 
 function remove_emacs {
-    if ! grep -Fxq "install_emacs" $COMPLETION_FILE; then
+    if [[ $(app_is_installed emacs) == "0" ]]; then
         return
     fi
     apt-get -y remove --purge emacs24
diff --git a/src/freedombone-app-gnusocial b/src/freedombone-app-gnusocial
index 903aae5c..3a4bd2db 100755
--- a/src/freedombone-app-gnusocial
+++ b/src/freedombone-app-gnusocial
@@ -337,7 +337,7 @@ function restore_remote_gnusocial {
 }
 
 function remove_gnusocial {
-    if ! grep -Fxq "install_gnusocial" $COMPLETION_FILE; then
+    if [[ $(app_is_installed gnusocial) == "0" ]]; then
         return
     fi
     nginx_dissite $MICROBLOG_DOMAIN_NAME
diff --git a/src/freedombone-app-gogs b/src/freedombone-app-gogs
index e3c9d36d..c95b2b08 100755
--- a/src/freedombone-app-gogs
+++ b/src/freedombone-app-gogs
@@ -396,7 +396,7 @@ function restore_remote_gogs {
 }
 
 function remove_gogs {
-    if ! grep -Fxq "install_gogs" $COMPLETION_FILE; then
+    if [[ $(app_is_installed gogs) == "0" ]]; then
         return
     fi
 
diff --git a/src/freedombone-app-hubzilla b/src/freedombone-app-hubzilla
index 2246c5f0..602bfbff 100755
--- a/src/freedombone-app-hubzilla
+++ b/src/freedombone-app-hubzilla
@@ -354,7 +354,7 @@ function restore_remote_hubzilla {
 }
 
 function remove_hubzilla {
-    if ! grep -Fxq "Hubzilla domain" $COMPLETION_FILE; then
+    if [[ $(app_is_installed hubzilla) == "0" ]]; then
         return
     fi
     echo $'Removing Hubzilla'
diff --git a/src/freedombone-app-ipfs b/src/freedombone-app-ipfs
index 7dcde766..7685fb33 100755
--- a/src/freedombone-app-ipfs
+++ b/src/freedombone-app-ipfs
@@ -151,7 +151,7 @@ function restore_remote_ipfs {
 }
 
 function remove_ipfs_go {
-    if ! grep -Fxq "install_ipfs_go" $COMPLETION_FILE; then
+    if [[ $(app_is_installed ipfs_go) == "0" ]]; then
         return
     fi
     systemctl stop ipfs
@@ -168,7 +168,7 @@ function remove_ipfs_go {
 }
 
 function remove_ipfs_js {
-    if ! grep -Fxq "install_ipfs_js" $COMPLETION_FILE; then
+    if [[ $(app_is_installed ipfs_js) == "0" ]]; then
         return
     fi
     systemctl stop ipfs
diff --git a/src/freedombone-app-irc b/src/freedombone-app-irc
index 60bd7ec2..c746d9ea 100755
--- a/src/freedombone-app-irc
+++ b/src/freedombone-app-irc
@@ -141,7 +141,7 @@ function restore_remote_irc {
 }
 
 function remove_irc {
-    if ! grep -Fxq "install_irc" $COMPLETION_FILE; then
+    if [[ $(app_is_installed irc) == "0" ]]; then
         return
     fi
     systemctl stop ngircd
diff --git a/src/freedombone-app-librevault b/src/freedombone-app-librevault
index aa1e73dc..9c15d239 100755
--- a/src/freedombone-app-librevault
+++ b/src/freedombone-app-librevault
@@ -104,7 +104,7 @@ function restore_remote_librevault {
 }
 
 function remove_librevault {
-    if ! grep -Fxq "install_librevault" $COMPLETION_FILE; then
+    if [[ $(app_is_installed librevault) == "0" ]]; then
         return
     fi
     iptables -D INPUT -p udp --dport $LIBREVAULT_PORT -j ACCEPT
diff --git a/src/freedombone-app-mumble b/src/freedombone-app-mumble
index b52a2467..bcd2a21f 100755
--- a/src/freedombone-app-mumble
+++ b/src/freedombone-app-mumble
@@ -145,10 +145,8 @@ function restore_remote_mumble {
 }
 
 function remove_mumble {
-    if !grep -Fxq "install_mumble" $COMPLETION_FILE; then
-        if ! grep -Fxq "install_voip" $COMPLETION_FILE; then
-            return
-        fi
+    if [[ $(app_is_installed mumble) == "0" ]]; then
+        return
     fi
     apt-get -y remove --purge mumble-server
     if [[ $ONION_ONLY == "no" ]]; then
diff --git a/src/freedombone-app-rss b/src/freedombone-app-rss
index 4a310c9c..66bb82aa 100755
--- a/src/freedombone-app-rss
+++ b/src/freedombone-app-rss
@@ -253,7 +253,7 @@ function restore_remote_rss {
 }
 
 function remove_rss {
-    if ! grep -Fxq "install_rss" $COMPLETION_FILE; then
+    if [[ $(app_is_installed rss) == "0" ]]; then
         return
     fi
     nginx_dissite $RSS_READER_DOMAIN_NAME
diff --git a/src/freedombone-app-searx b/src/freedombone-app-searx
index b948b7bd..d68b4489 100755
--- a/src/freedombone-app-searx
+++ b/src/freedombone-app-searx
@@ -92,7 +92,7 @@ function restore_remote_searx {
 }
 
 function remove_searx {
-    if ! grep -Fxq "install_searx" $COMPLETION_FILE; then
+    if [[ $(app_is_installed searx) == "0" ]]; then
         return
     fi
     systemctl stop searx
diff --git a/src/freedombone-app-sip b/src/freedombone-app-sip
index 00506c1a..220a7adc 100755
--- a/src/freedombone-app-sip
+++ b/src/freedombone-app-sip
@@ -107,7 +107,7 @@ function restore_remote_sip {
 }
 
 function remove_sip {
-    if ! grep -Fxq "install_sip" $COMPLETION_FILE; then
+    if [[ $(app_is_installed sip) == "0" ]]; then
         return
     fi
     iptables -D INPUT -p udp --dport $VOIP_TURN_PORT -j ACCEPT
diff --git a/src/freedombone-app-tahoelafs b/src/freedombone-app-tahoelafs
index f448d1af..b39d9b83 100755
--- a/src/freedombone-app-tahoelafs
+++ b/src/freedombone-app-tahoelafs
@@ -178,7 +178,7 @@ function restore_remote_tahoelafs {
 }
 
 function remove_tahoelafs {
-    if ! grep -Fxq "install_tahoelafs" $COMPLETION_FILE; then
+    if [[ $(app_is_installed tahoelafs) == "0" ]]; then
         return
     fi
     iptables -D INPUT -p udp --dport $TAHOELAFS_PORT -j ACCEPT
diff --git a/src/freedombone-app-tox b/src/freedombone-app-tox
index 9243b93c..d3d17162 100755
--- a/src/freedombone-app-tox
+++ b/src/freedombone-app-tox
@@ -189,7 +189,7 @@ function restore_remote_tox {
 }
 
 function remove_tox_node {
-    if ! grep -Fxq "install_tox_node" $COMPLETION_FILE; then
+    if [[ $(app_is_installed tox_node) == "0" ]]; then
         return
     fi
 
@@ -211,7 +211,7 @@ function remove_tox_node {
 }
 
 function remove_tox_avahi {
-    if ! grep -Fxq "tox_avahi" $COMPLETION_FILE; then
+    if [[ $(app_is_installed tox_avahi) == "0" ]]; then
         return
     fi
     cd $INSTALL_DIR/toxid
@@ -221,7 +221,7 @@ function remove_tox_avahi {
 }
 
 function remove_tox_client {
-    if ! grep -Fxq "install_tox_client" $COMPLETION_FILE; then
+    if [[ $(app_is_installed tox_client) == "0" ]]; then
         return
     fi
 
diff --git a/src/freedombone-app-webmail b/src/freedombone-app-webmail
index 34554d6b..d873aa24 100755
--- a/src/freedombone-app-webmail
+++ b/src/freedombone-app-webmail
@@ -119,7 +119,7 @@ function restore_remote_webmail {
 }
 
 function remove_webmail {
-    if ! grep -Fxq "install_webmail" $COMPLETION_FILE; then
+    if [[ $(app_is_installed webmail) == "0" ]]; then
         return
     fi
     nginx_dissite webmail
diff --git a/src/freedombone-app-wiki b/src/freedombone-app-wiki
index 7fbc84c0..ef90d32a 100755
--- a/src/freedombone-app-wiki
+++ b/src/freedombone-app-wiki
@@ -233,7 +233,7 @@ function restore_remote_wiki {
 }
 
 function remove_wiki {
-    if ! grep -Fxq "install_wiki" $COMPLETION_FILE; then
+    if [[ $(app_is_installed wiki) == "0" ]]; then
         return
     fi
     function_check remove_onion_service
diff --git a/src/freedombone-app-xmpp b/src/freedombone-app-xmpp
index bb434332..6e525132 100755
--- a/src/freedombone-app-xmpp
+++ b/src/freedombone-app-xmpp
@@ -210,7 +210,7 @@ function configure_firewall_for_xmpp {
 }
 
 function remove_xmpp_client {
-    if ! grep -Fxq "install_xmpp_client" $COMPLETION_FILE; then
+    if [[ $(app_is_installed xmpp_client) == "0" ]]; then
         return
     fi
     apt-get -y remove --purge profanity
@@ -219,7 +219,7 @@ function remove_xmpp_client {
 
 function remove_xmpp {
     remove_xmpp_client
-    if ! grep -Fxq "install_xmpp" $COMPLETION_FILE; then
+    if [[ $(app_is_installed xmpp) == "0" ]]; then
         return
     fi
     iptables -D INPUT -p tcp --dport 5222:5223 -j ACCEPT
diff --git a/src/freedombone-app-zeronet b/src/freedombone-app-zeronet
index bf14880b..b72ba9f3 100755
--- a/src/freedombone-app-zeronet
+++ b/src/freedombone-app-zeronet
@@ -89,7 +89,7 @@ function restore_remote_zeronet {
 }
 
 function remove_zeronet_blog {
-    if ! grep -Fxq "install_zeronet_blog" $COMPLETION_FILE; then
+    if [[ $(app_is_installed zeronet_blog) == "0" ]]; then
         return
     fi
     if [ -d $MESH_INSTALL_DIR/zeronet/ZeroBlog ]; then
@@ -100,7 +100,7 @@ function remove_zeronet_blog {
 }
 
 function remove_zeronet_mail {
-    if ! grep -Fxq "install_zeronet_mail" $COMPLETION_FILE; then
+    if [[ $(app_is_installed zeronet_mail) == "0" ]]; then
         return
     fi
     if [ -d $MESH_INSTALL_DIR/zeronet/ZeroMail ]; then
@@ -111,7 +111,7 @@ function remove_zeronet_mail {
 }
 
 function remove_zeronet_forum {
-    if ! grep -Fxq "install_zeronet_forum" $COMPLETION_FILE; then
+    if [[ $(app_is_installed zeronet_forum) == "0" ]]; then
         return
     fi
     if [ -d $MESH_INSTALL_DIR/zeronet/ZeroTalk ]; then
@@ -125,7 +125,7 @@ function remove_zeronet {
     remove_zeronet_blog
     remove_zeronet_mail
     remove_zeronet_forum
-    if ! grep -Fxq "install_zeronet" $COMPLETION_FILE; then
+    if [[ $(app_is_installed zeronet) == "0" ]]; then
         return
     fi
     iptables -D INPUT -i $WIFI_INTERFACE -p udp --dport $ZERONET_PORT -j ACCEPT