Hello,
Well it depends what you're using. M3u and Xtream login and password, I would say TiviMate is best.
If you're using stalker Portals then it's a hit and miss with all the apps.
Not all portals work on Tivimate and vice versa.
I have tried, iMPlayer, Tivimate, STBEmu Pro, IPTV extreme, Ultimate IPTV Playlist Loader pro and OTT navigator.
I use the following three apps on a daily basis depending on the portal.
1.Tivimate
2.Ultimate IPTV Playlist Loader Pro
3. STBEmu Pro.
Hope this information helps.