this is not open source. from their license:

Subject to the terms of this license, we grant you a non-transferable, non-exclusive, worldwide, royalty-free license to access and use the code solely for the purposes of review, compilation and non-commercial distribution.

note how this explicitly leaves out modification.

You may provide the code to anyone else and publish excerpts of it for the purposes of review, compilation and non-commercial distribution, provided that when you do so you make any recipient of the code aware of the terms of this license, they must agree to be bound by the terms of this license and you must attribute the code to the provider

once again, they exclude modification of the code.

no forks can be made because they aren't allowed to modify the app in anyway.

Additionally, the termination clauses say that they can just terminate your rights to use the code if they feel like it, no other reason needed. This is a direct attack against open source.