Here's my simple setup, Joanne:

1. Lead sheets with chords, lyrics and melody on iPad Pro (large enough for even my 69-year-old eyes to read). They're in pdf format on Documents 5 File Manager, which lets me flip to the next song. (I don't sing, but I like to "hear" the lyrics while I play.)
2. BIAB on regular iPad, using BIAB's iPad/iPhone app. (Now if PGMusic would just update it so I can flip to next song on that!)
It all sits on my music stand so that the audience sees no computer screens, and the BIAB highlighter reminds me where I am when I'm interrupted or suffer a senior moment.
Memorization's not for me. I play mostly jazz standards. In my opinion, it's a lot harder to remember chord changes for those than for most pop songs.

Cheers! -Alastair