Fender Songs is the company's latest and TL;DR it teaches you how to play songs... sort of. It's a chord library, meaning that you can pull up a song that you want to learn and it'll show you the chords to play. You can see them laid over the lyrics in a pretty traditional layout, or in a scroll that displays the chords you're supposed to play as moving bars synced with the lyrics. The more traditional layout, where the chord fingerings are all shown at the top and the chord names are simply placed in the appropriate spot in a lyric sheet is great for quickly studying a song, but is a bit information dense for a phone, and not really practical for playing along with. And, at least in the preview version of the app, it was a little buggy. It would always highlight the right chord, but often in the wrong place. For example, in Rihanna's Stay there are three Am chords associated with many individual lines, and rather than highlight each Am in order it would often just highlight the first one three times.
The scroll is much better for practicing, and really that's what Songs is all about. It's not just a glorified reference book. It's actually designed to play along with. And while there are simple MIDI backing tracks (which at least in the beta version are basically unrecognizable), what sets Fender's app apart from other chord libraries is that it integrates with Apple Music. This means that you can pull up your favorite Billy Eilish track and the app will feed you the chords and display the lyrics in time with the actual song.
Now, to be clear you will need an Apple Music subscription for this to work. And, unless you're paying for a Fender Songs subscription, the library of tunes you have to pull from is pretty limited. And I want to be clear here: Songs ain't cheap. At $42 a year or $5 a month, it's a pretty hefty investment for an interactive chord book.(On the plus side, a yearly subscription also nets you 10-percent off gear from Fender.)
Part of the reason it's so expensive though, is because Fender worked with artists, labels and Apple to get everyone on board. There are definitely other chord libraries out there, but most of them aren't endorsed by the labels, the artists don't make any money off them and they don't play the actual songs (and if they do, they're probably in some sort of legal grey area). I'm not going to say that makes it worth paying for, but it at least helps explain the steep price.
In addition to showing you the chords to a song, there's also a record mode. Here the app shows the chord changes and lyrics, but doesn't play a backing track, and instead uses your phone's front facing camera to capture your performance. You can also build a set list, where you collect songs to practice or perform.