UTMA account options for low balance

[PDXTabs]

Does anyone have any recommendations for where to open a UTMA account for my son? There wouldn't be very much in it to start, maybe $200.

EDITed to add - there are conflicting reports as to when or whether M1 Finance allows UTMA accounts. Their FAQ says no but the paper application says yes. Reddit says mid-2019.

[Kem]

I hold my daughters UTMA at Fidelity - this is where their gift money or small jobs money goes.

The younger daughters was opened with around $300.  Currently I invest their small funds into ITOT as it is inexpensive vs VTI.  New contributions will be going into Fidelity zero fee funds