A one-time price describes a payment arrangement, not guaranteed lifetime service or better training results.
Check the actual offer
Read the purchase screen for the product, included access and any recurring charge. Do not infer current availability from an old article title.
Distinguish purchase restoration from data restoration
Restoring an entitlement and restoring workout records are different tasks. Confirm both with the developer if they matter to you.
What Weights currently documents
The released Weights listing describes monthly and yearly Premium subscriptions. This website does not promise a one-time or lifetime offer. Use the current in-app purchase screen for available options.
Read the offer, not just the headline
A “no subscription” claim can refer to a free tier, a one-time purchase or one part of a product. Open the current offer and check what is included, which platform it covers, and whether the feature you need is sold separately. Compare the amount shown for your region. If the product also offers subscriptions, verify which option you are selecting before confirming a purchase. This article does not establish that Weights currently offers a lifetime purchase.
Check what happens to your records
Before choosing on price alone, find out how older sessions are viewed and whether an export can be opened outside the app. Saving records and being entitled to every historical view are different questions. Ask support when the published explanation is unclear. Do not assume an export can be imported into another tracker or restored automatically; a readable PDF and a re-importable backup have different purposes.