Effective October 21, 2026
Terms · Quellfern
These terms cover Quellfern (formerly Spam-Call Scrubber) for iPhone, iPad, and Android, from Montgomery Appworks LLC in Oklahoma. Its subtitle is Spam Call Blocker. The privacy policy is at /quellfern/privacy.
The app
The free tier of Quellfern includes basic FTC-list blocking, the allow list and block list you keep on the 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. Blocking runs on the device: an iOS CallKit Call Directory extension on iPhone and iPad, and CallScreeningService on Android. No phone number leaves the device. There is no account or login.
Blocking and labeling are best-effort
Blocking and labeling are best-effort. Legitimate calls may be blocked, and some spam may get through.
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. Quellfern Pro is an optional auto-renewing subscription with a monthly plan, an annual plan, and a free trial. The price is shown in the app and in the App Store or Google Play before you purchase. You can cancel anytime in the App Store or Google Play settings. Purchases go through Apple and Google via RevenueCat.
Auto-renewal, free trials, and cancellation
Payment is charged to your Apple ID or Google account when you confirm the purchase. A free trial converts to a paid plan unless you cancel at least 24 hours before the trial ends. Monthly and annual plans renew automatically for the same period unless you cancel at least 24 hours before the current period ends. Your account is charged for renewal within the 24 hours before the current period ends.
If you purchase a subscription during a free trial, any unused part of the trial is forfeited.
On iPhone or iPad, manage or cancel the subscription in Settings, under your Apple ID, then Subscriptions. On Android, manage or cancel it in Google Play, under Payments and subscriptions. Deleting the app does not cancel the subscription.
Apple’s license
If you installed the app from the Apple App Store, it is licensed under Apple’s standard Licensed Application End User License Agreement.
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.
Changes
If these terms change, the effective date at the top of the page changes with it.
Oklahoma law
These terms are governed by the laws of the State of Oklahoma.
Contact
Montgomery Appworks LLC, Oklahoma