One of The 13 Best Migraine Apps of 2013 by Healthline.com.

One-stop shop to manually enter migraine episode (time, location, severity, symptoms, triggers, and treatments). The innovative design provides pleasant yet intuitive user experience to easily navigate, input, view, and analyze history via lists, charts, and statistics. Can also log avoidance of food, medication, etc.

Features

Logs

Migraine can cause sever pain. Knowing its pattern (when and why it occurs, how to treat) may help better deal with it accordingly and significantly improve life quality. Log each episode's time, location, severity, symptoms, triggers, and treatments with Migraine Stop.
Pie chart and statistic table analyze logs and show top triggers (up to 5). Avoiding the triggers may help minimize migraine occurrence.

Avoidance

You may have noticed that certain foods, medications, etc might trigger migraine. Log them with name, reason to avoid, scale (slightly avoid to totally avoid). Use the list as reference before you consume food, medication, etc.

In-App Purchase Features

For a nominal extra, you will get such amazing features as:

No Ads: Completely remove advertisements and provide even better user experience.
Report: Generate reports of episode and avoidance in pdf format, including lists, charts and statistics, and customizable. Then email, wirelessly print from the device, or Open In your pdf readers on devices. It has never been easier to share information with your healthcare provider
Backup and Restore: Securely backup your data and restore it when necessary (e.g. on data loss or data import to other iOS compatible devices) via Wi-Fi.

Note:
1. You must not rely on the information on this app, or site through this app, as an alternative to medical advice from your healthcare provider. Always consult with your healthcare provider.
2. This app does not import data from devices or other data sources (except your own backup). All data need to be entered.