Call me tardy to the party, but I've just recently picked up both MoDrum and BassLine from Finger Pro. I'm really having fun playing with these two together. These apps are definitely like peanut butter & jelly.
MoDrum is a drum synth aimed at capturing the classic 808 drum sound. A few years ago, I was not a fan of these sounds at all. I grew up on classic rock, and these "drum" sounds were poison to my ears. But I've become more interested in electronic music these days, and have even seen how electronic drums can be incorporated into guitar-heavy music in very pleasing ways.
The interface of MoDrum is very simple to use, if you are familiar with step sequencers. As the app is universal, the interface is slightly different on the iPad from the iPhone, but all of the same features are there. You have 11 different drum choices, including the ubiquitous bass drum, snare, clap, open or closed hat, you get the picture. With a 32 step sequencer, you can choose not only which steps to place hits, but also choose the accent pattern for certain steps as well.
The app is Audiobus and Inter-App Audio (IAA) compatible, and as I said, is universal as well. This is an app that I do keep on my iPhone, due to its small size and ease of use. MoDrum does have some limited built-in effects as well, including dotted eighth delay, a compressor, overdrive distortion, and some reverb. If I'm not mistaken, I believe these are global effects, and not per instrument.
Here's a demo track from the developer:
BassLine is a great companion app to MoDrum. Made to emulate a TB-303, you will definitely know what to expect from the sounds here. The interface is in the classic "one note per step" style that you may be familiar with from apps like Rhythm Studio (or, obviously the TB-303). All the expected controls are here, including accent, slide, and octave selector. One great feature about BassLine is the two X/Y pads that allow you to control the envelope and frequency.
The app has four different waveforms to choose from (sawtooth, square, pulse, and saw/triangle). Along with an LFO, there is also a delay and amplifier for some distortion.
BassLine, like MoDrum, is also universal. The layout is consistent across both devices. And as with MoDrum, it is also Audiobus and IAA compatible.
You can create up to four different patterns in BassLine, which can be switched on the fly (after the current pattern finishes). This creates some great "live" playability, so you're not just cranking the same repetitive 16 note pattern.
The beauty of these apps are their simplicity and immediate level of entry. Anybody could pick these apps up and get going with them. In fact, my two daughters, ages 7 and 5, were able to figure these out immediately and start programming some basslines. The MIDI and clock sync of these apps make them almost a required pair. Change the BPM in MoDrum, and it changes the BPM in BassLine automatically. So nice.
There are a lot of choices for drum synthesizers and TB-303 clones in the iOS marketplace. Admittedly, some of the drum synthesizers are more flexible and deeper than MoDrum. But I really like having both of these and just cranking out tracks. I don't need to worry about too much programming. These app are also very affordable.
You can check out the App Store links below for each app. As of the time of this writing, they both sell for $3.99 USD each. But, there is an app store bundle for both for only $4.99. For some "Apple/iTunes" reason, I can't link to the App Bundle, but click on one of the links below to bring you to the App Store. Kind of a no-brainer for me, if you're into this style of music.[app 298147000] [app 408872480]