\X is the Unicode grapheme cluster (a visual character including all combining marks)

Most Android software is ad-sponsored so this comes quite as a shock when your previous work place was all with ad-blockers and FOSS.

• Android open-source store: f-droid

Location services:

• GPS Status (ad-ware)
• Map application that can use OSM: MapQuest (free)
• OsmAnd is the best I found so far, good offline+offline search support

Locale switching:

• Nice device locale switching utility: Quick Locale Switcher doesn’t work, unfortunately
• Locale switching widgets don’t work in 5.1
• LocaleSwitch

Network:

• Connectbot (SSH Client)
• Firefox browser
• K9 Mail
• Xabber
• Siacs Conversations

Child care:

• working lockdown app: SureLock (expensive, 50€)
• Markers Doodle app

Misc:

• 920 Text Editor
• Ugly as hell but free of ads Chinese lunar calendar
• Lunar calendar
• Comic reader can read some comics on the net (source code)
• MuPDF

SYNC:

• one way calendar sync (to android, buggy but free) Caldav Sync
• demo contact sync CardDAV-Sync free beta
• DAVdroid

Very nice dependency-free dav server to set up on your device: Radicale