I will answer myself due to lack of responses.
If you press and hold in the words “more games” at the bottom of the games list, it will appear a new window where you can introduce the name of the game and the url to download it. This will add the new game to the list and the special Incant’s file system.
Nevertheless Incant won’t do any transcript, crashing when you try. So it seems that, for glulxe games on Android, we can only use Text Fiction under Thunderword by now.
Fabularium [alternate F-droid link] also supports Glulx (and transcripts) under Android, although the transcripts are a bit difficult to find once they’re saved (look at the game’s About info to find its ID, then go to that folder in Fabularium’s GameData folder).
Fabularium supports transcripts, but transcripts for Glulx games are glitched and don’t record commands. So if you want a proper transcript of a Glulx game, Text Fiction+Thunderword is the only working Android option.
Yes, as you said, glulx transcripts aren’t made properly becouse don’t register the input of the player.
I wish someone could fix it.
I was exploring an alternative for TF + TW with Incant, but don’t make any transcript. Twisty crashes after input the transcript’s name.
I prefer Son of Hunky Punky over Fabularium becouse the z5 transcripts are appended automatically.