Hi @Imaan_1538 --
While developing the Beat Box project, I connected a MidiVox audio shield to my littleBits Arduino.
The attached picture shows the MidiVox connected to a regular Arduino. I usually build Arduino shields with headers that have long pins on the bottom and female receptacles on the top. So, in order to connect the shield to the littleBits Arduino, I connected the shield pins to the corresponding pins on the Arduino using male-to-female jumper wires.
Your sketch will need to read/write the Arduino pins to which the shield(s) are connected. If the GSM or GPS shield is accessed through a library, then you may (will) need to change the pin assignments in the library to match your connections
Output pins D5 and D9 are buffered, that is, D5 and D9 are each driven through an OP AMP. The buffering affects the signal timing when communicating with garden variety digital circuits like the GSM/GPS shields. To save yourself frustration, I don't recommend using these buffered pins with the shields. Pin D1 is unbuffered and is OK. The ICSP signals and D10, D11 and D13 are also unbuffered.
The Beat Box project uses the ICSP signals in order to access the Arduino's Small Peripheral Interface (SPI). The following page on my web site has some tips that you mind find helpful, especially on using a breadboard as a jig while soldering pins to the Arduino.
Hope this info helps -- pj