[Guide] Getting an android apk
Well unfortunately many Blackberry apps are not working as supposed to any longer, because of missing certificates and changes to services they need to connect to in the backend.
There are some good threads here listing apps that are still good to run and use, or modified apk's to suit the BB10 OS:
BB10 OS native
Leo's Android adoptions
In case one need to download stuff that is not listed in the above threads, you might want to use F-Droid for open source apk's.
F-Droid Market
If that's all you need, you might be happy. If you have time and want or need to check out more apk's, you can download them straight from Google Playstore with help of the services here:
APKcombo
APK support
Personally I prefer the later, because I can filter for 4.3 (API 16) apk's and use a setting for Samsung S3 for the search
Just for a little more comfort I search with APKcombo first and use the name of the APK I found as an input for APK Support web site eg. com.facebook.mlite for FB Messanger lite
In case you do some URL hacking you can use APK Combo as follows in case you know the apk name. This example is for FB lite messenger:
https://apkcombo.com/en-de/apk-downloader/?device=
&arch=armeabi-v7a&android=4.3&q=com.facebook.mlite
While using any of the above to get files from Google Play to download to your device, you may want to install SAI (Split application installer) to install split apk's as well
SAI download
In case you have any recommends of apk's that work flawless, please comment below