Downloaded to take advantage of the advertised promo of lifetime premium for $0.00. The option to purchase lifetime premium for $0.00 is available as an IAP, but the purchase button is unresponsive when that option is selected. The purchase button is, however, quite responsive when the weekly option ($6.99/wk) or the monthly option ($12.99/mo) is selected. Not sure if this is a bug or a bait and switch tactic.
If it’s not resolved with enough time for users to take advantage of the promo, assume this dev operates in bad faith with no regard for users. If the issue is rectified, I will update my review.