|
Apps are kind of a pain. You need two and keeping them up to date is a chore.
I’ve done some iPhone apps. No android.
Website easier. Stick it in your cloud provider du jour.
All phones have a browser.
If you want proper redundancy - as in all phone and Wi-Fi is out - a downloadable file on each phone is going to be easiest. You just need to be able to push updates.
There are plenty of SMS services for push notifications if you need those.
|