Many pilots purchase an iPad for use with Foreflight. Before purchasing an iPad, be sure to review the Foreflight iPad Buyer’s Guide (published by Foreflight).
In order to get an accurate GPS position with Foreflight, you must have either an iPad with wifi + cellular (wifi only models do not have an onboard GPS), or wifi iPad and an additional external GPS. Note that cellular service is not required to use the onboard GPS, just cellular capability.
There are several options for external GPS for an iPad if you have a WiFi only tablet.
Bad Elf GPS (budget friendly GPS only)
The Bad Elf GPS connects via the lightning port but has a passthrough port so you can charge your device while it is in use. It is the most budget friendly at approximately $95.
Purchase a Bad Elf GPS with Lightning Connector here
Foreflight Sentry Mini (GPS, ADS-B In)
The Foreflight Sentry Mini is $299, and in addition to a GPS is an ADS-B receiver for free weather and traffic info. It is easily mounted with the included suction cup mount.
Purchase a Foreflight Sentry Mini ADS-B Receiver here
Foreflight Sentry (GPS, ADSB-in, AHRS, CO Detection)
The slightly larger Foreflight Sentry has the same features as the Sentry Mini and also has a Carbon Monoxide detector, and AHRS sensors, which when used with Foreflight gives you a fairly accurate Attitude Indicator and Roll/Rate of turn indicator. These additional features up the cost to approximate $499. The Sentries connect to your iPad via WiFi and can support multiple devices at once. I use a Foreflight Sentry when I am instructing in rental aircraft. It is easily mounted using the included suction cup mount.
Purchase a Foreflight Sentry ADS-B AHRS here
Garmin GDL39 / 39-3D (GPS, ADSB-In; AHRS and XM Radio and Weather 39-3D only)
The GDL 39 series is now supported by Foreflight using a Bluetooth connection. It is also compatible with Garmin Pilot, a variety of Garmin avionics, such as a the Area 796/795, Aera 500 series, GPSMAP® 696/695, G3X™ flight display and select Garmin Pilot accessories. I have the 3D model in my Searey connected to Garmin avionics and I also use it with Foreflight. I personally have found the XM weather to be a little less laggy than ADS-B weather. and enjoy the option of XM radio while flying. It is portable but can also be mounted in an aircraft and connected to an external antenna. It has an onboard battery but wiring harnesses are available to connect to a cigarette lighter, a USB port, or (as in my case) directly to the electrical system of an aircraft. The GDL39 Can be found for around $499, while the GDL 39-3D runs $800 to $900 depending on options (such as external wiring harness). The GDL 39-3D has been discontinued and can often be found on ebay at a reduced price.
Garmin GDL 39-3D has been discontinued is available from some sellers
Garmin GDL50/52 (GPS, AHRS, ADS-B; XM Receiver – 52 only)
Similar to the GDL 39-3D, but does not offer XM weather and radio. Roughly $699. The GDL 52 also offers XM Weather and Radio, but is substantially more expensive at roughly $1100.
Purchase a Garmin GDL 50 here
Purchase a Garmin GDL 52 here
Stratux (Assembled Kit, GPS, AHRS, ADS-B In)
Another budget friendly (about $299) option that supports a number of apps (ForeFlight, FlyQ EFB, Navigator, AvNav, WingX, Avare EFB, FltPlan Go, DroidEFB, AerovieReports, Avplan EFB, iFly GPS, DroidEFB, OzRunways EFB). The Stratux is sold both as a kit or pre-assembled.
Purchase a Pre-Assembled Stratux here