Wavelet for Android has the potential to be so much more than what it appears to be at first sight. Yes, it offers the whole AutoEQ database of settings. But with a little bit of work you can use whatever curve you want. I have used it to EQ my smartphone when connected to my car stereo too.
With a mix of the instructions from here:
https://medium.com/@jaakkopasanen/make-your-headphones-sound-supreme-1cbd567832a9 and REW use... you can end up with AutoEQ commandline like this:
python autoeq.py --input_dir="MyData" --output_dir="MyResults" --compensation="compensation/Harman_Target.csv" --equalize --parametric_eq --max_filters=20 --fixed_band_eq --fc 20,21,22,23,24,26,27,29,30,32,34,36,38,40,43,45,48,50,53,56,59,63,66,70,74,78,83,87,92,97,103,109,115,121,128,136,143,151,160,169,178,188,199,210,222,235,248,262,277,292,309,326,345,364,385,406,429,453,479,506,534,565,596,630,665,703,743,784,829,875,924,977,1032,1090,1151,1216,1284,1357,1433,1514,1599,1689,1784,1885,1991,2103,2221,2347,2479,2618,2766,2921,3086,3260,3443,3637,3842,4058,4287,4528,4783,5052,5337,5637,5955,6290,6644,7018,7414,7831,8272,8738,9230,9749,10298,10878,11490,12137,12821,13543,14305,15110,15961,16860,17809,18812,19871 --q 1.41
That gives you a custom profile to import in Wavelet. You can import as many as you want. You name the txt file as you want the profile to be called. You import in Wavelet and you can then search for it in the database and apply it at will.
It's not parametric, but with 127 bands (43 from 20Hz to 200Hz) you certainly don't lack the resolution to fix things correctly.
Another example of what it allows: I use custom IEMs. Their FR has been measured and AutoEQ provides Harman target values. But I prefer Oratory1990 curve for IEMs. With a bit of work it was possible to use that and import it in Wavelet.