It has been a few years since ive done any kind of android development but i would be more than happy to share some safety/security features as well as some potential implementations for alot of usecases i think youre missing.

The MAXS framework could do a lot to take this to the next level. http://projectmaxs.org/homepage/

If you wanted to create something that generates revenue offer your xmpp/lifealert system as a hosted solution and sell refurbished Motorola Z2 Forces pre-installed/configured w a custom rom.

I have done this exact same thing once before as part of a b2b/b2g saas solution and would love to contribute freely (wireframes, process diagrams, branding/design, documents, etc#). All i would ask for in return is your pov/guidance on some of my own efforts.

LMK