Designed on top of the existing Bluetooth v4.0 standard, the CheepSync framework utilizes low-level time- stamping and comprehensive error compensa- tion mechanisms for overcoming uncertainties in message transmission, clock drift, and other system-specific constraints. CheepSync was imple- mented on custom designed nRF24Cheep bea- con platforms (as broadcasters) and commercial off-the-shelf Android ported smartphones (as passive listeners). We demonstrate the efficacy of CheepSync by numerous empirical evaluations in a variety of experimental setups, and show that its average (single-hop) time synchronization accura- cy is in the 10 s range.