Apps can say they work with Gearslip, and each recommended app gets its own page

An app adds one meta-data line to its manifest and Gearslip marks it Works with Gearslip in the
Recommended apps list. Tapping an app opens its page, with an Open or Get button. A README badge
for app developers is in docs/badge, documented in BUILDING_APPS.md.

gearslip/src/main/res/values/strings.xml

@@ -96,6 +96,14 @@
     <string name="recommended_about_ytm">A YouTube Music player.</string>
     <string name="recommended_about_antennapod">Podcasts, chapters and all.</string>
     <string name="recommended_about_rfsentinel">Spots trackers and cameras nearby.</string>
+    <!-- The mark on apps that declare they work with Gearslip, and the list's heading for them. -->
+    <string name="works_with_gearslip">Works with Gearslip</string>
+    <!-- One app's page, opened from Recommended apps. %1$s is the app's name. -->
+    <string name="app_page_on_car">Gearslip shows it on the car screen.</string>
+    <string name="app_page_get_hint">Install it, and Gearslip shows it on the car screen.</string>
+    <string name="app_page_open">Open %1$s</string>
+    <string name="app_page_get">Get %1$s</string>
+    <string name="app_page_github">View on GitHub</string>
 
     <!-- Settings -->
     <string name="settings_title">Settings</string>