Effective October 21, 2026
Privacy · Quellfern
This policy covers Quellfern (formerly Spam-Call Scrubber) for iPhone, iPad, and Android, published by Montgomery Appworks LLC in Oklahoma. Its subtitle is Spam Call Blocker.
What the app does
The free tier includes basic FTC-list blocking, the allow list and block list you keep on your device, and Balanced, Strict, and Label-only modes. The blocklist is built from the FTC’s public Do Not Call complaint data and ships with the app. On the free plan the app rebuilds that list weekly. New list data arrives only through app updates. No phone number leaves the device.
Quellfern Pro
Quellfern Pro is the paid subscription tier. It adds neighbor-spoof protection, quiet hours on Android, blocking by pattern and number range, and area-code and country blocking on Android. Neighbor-spoof protection labels lookalike numbers on iPhone. On Android it can label or block them. Quiet hours are Android-only. On Pro, the app rebuilds the FTC complaint list that ships inside the app every day. On the free plan it rebuilds that list weekly. New list data arrives only through app updates. No phone number leaves the device.
A future optional live-lookup feature would be disclosed here before it’s enabled.
Blocking stays on your device
Blocking runs on the device. On iPhone and iPad it uses an iOS CallKit Call Directory extension. On Android it uses CallScreeningService. Incoming call information is not uploaded. The app does not read or upload your contacts. Personal block and allow lists stay on the device.
Purchases
Purchases go through Apple and Google via RevenueCat. RevenueCat receives an anonymous app user ID and store receipts. There is no account or login in the app.
Ads and analytics
Quellfern has no ads and no third-party analytics.
Providers
- Capacitor
- RevenueCat, for subscriptions
- FTC Do Not Call complaint data, which is public. No user data is sent to the FTC.
Children
Quellfern is not directed at children under 13.
Deleting your data
Deleting the app removes local data, including personal block and allow lists and the FTC blocklist stored on the device. Purchase records are held by Apple, Google, and RevenueCat.
Changes
If this policy changes, the effective date at the top of the page changes with it.
Contact
Montgomery Appworks LLC, Oklahoma