FLAC Players for iOS

Looking at FLAC players for an old iPhone I want to repurpose into a listening station (that I think I’m going to build around the JDS Atom 2 stack?). Quick synopsis of the few I’ve looked at so far:

• VOX. Premium features, including basics like a parametric EQ and EQ presents, an ad-free experience, gapless playback, etc., are locked behind a subscription. $49.99 yearly or $4.99 monthly. Once I saw that pricing I stopped looking at it.
• Flacbox. Natively connects to WebDAV, SMB, etc. servers, along with the usual litany of cloud services. Premium is a lifetime purchase of $14.99 (with a free trial), and includes ad delete, an unlimited number of cloud services, downloading albums and playlists, an unlimited number of playlists and songs in a playlist, etc. Has a 10-band EQ with precise ± decibel settings per octave. A contender.
• Doppler. A 7 day free trial and then a one time $9 charge. Doesn’t connect directly to servers but helpfully links to instructions for how to mount servers in the Files app. No equalizer. Nice interface.
• FLAC Player+. Also uses the Files app (under Settings / iCloud Drive / Browse), or provides a quick and dirty (if somewhat clunky) web browser based way to upload files directly into the app. 10 band EQ. Removing ads is a $0.99 one time charge. It’s a bare bones experience but it seems to work well enough and the price is certainly right. This is likely what I’m going to use.

Screenshot showing four FLAC player apps

More to follow, once I can get the iPhone hooked up (via an Apple Lightning to USB3 Camera Adapter) to a DAC/Amp that can properly drive the HD660S2 etc. (Contenders include the above linked JDS stack ($279), the Schiit Modius + Midgard ($448 plus an XLR4 adapter) or Jotunheim ($499-599 depending on DAC module), maybe the Topping DX5 ($249 on drop.com, also plus an XLR4 adapter)...)