Tuning 808s in Garageband is really quite easy, and it doesn't take as much work as you think.
While creating sliding 808s in Garageband is possible with the Deep Sub Bass Synth, it's much better to use third-party plug-ins.
You can use parallel compression in Garageband in two different ways.
Garageband does have autotune and pitch correction by default, however, third party plug-ins such as Melodyne or MAutoPitch are better options.
The best way to add an 808 bass to a project in Garageband iOS is to find an 808 bass sample and then load it into the sampler. After you've loaded the sample into Garageband iOS, you then have an...
How to add sustain to notes in Garageband, Logic, and other DAWs, using the software, Melodyne.