The bundle allows you to upgrade from any app in the Polar Scope Align family, to the Pro Watch version that contains them all, by paying only the price difference. It also allows you to run Xasteria Plus and Bubble level watch (part of PS Align Pro Watch) as separate apps, and the Polar Scope Align Pro & Pro Watch versions on the same device (with different settings). About Polar Scope Align Pro Watch: Through the years, apart from the most reliable Polar Alignment app, PS Align pro has become the astronomer's swiss-army knife. Polar Scope Align will calculate the position of Polaris or σ Octantis in your Polar Scope reticle for your location (using your phone's GPS or manually), allowing a quick and accurate polar alignment. It is one of the few programs that are accurate in lower latitudes by correcting for atmospheric refraction. It will even allow you to measure and correct a centering error of the reticle. In the settings you can select from a vast collection of reticles, one that matches your own. Pretty much every reticle in the market is supported: iOptron old & new, Astro-Physics RAPAS & PASILL, various versions of Takahashi EM-10/11/200/400/500, NJP, PM-1, P2-Z, the latest Orion / Skywatcher, the Classic Skywatcher / Orion / Celestron / Meade / EXOS2 / Bresser, the Telrad, Rigel QuikFinder, a couple for Astrotrac / Losmandy / Kenko / Avalon, the Vixen Atlux/SX/SXD/SXP/AXD/GP/GP-DX/Polarie Polar Axis Scopes, a Konus and several Polar Finders: Tuthill, Explore Scientific 8x50, Meade 9x60, Vixen Polaris, Celestron 7x50, Carton Optical. PoleMaster help view for South Hemisphere users. The Pro Watch version has all the features of Polar Scope Align Pro, with the addition of an Apple Watch app featuring: -Graphic & Text display of polar alignment. -Weather view. -Bubble level. -Day alignment. -Moon/Sun rise/set/twilight/phase. Feature list: -Accurate calculation of Polaris or Sigma Oct for any date and location, including effect of atmospheric refraction (and annual aberration, nutation). Most other apps do not perform precision calculations, so please only compare app readings to accurate sources (USNO etc). -Use device time/date and GPS location, or manually enter your own. -Location manager with favorite locations, list of recent locations, online search and offline world database. -Full app in red-color (or alternative) night mode - tools switchable to daytime view. -Deep Space Object (DSO) Database with 13000+ objects from several catalogs (Messier, Caldwell, NGC, IC, Herschell 400, Sharpless 2). Search, apply filters, sorting, download DSS color images for all items, or get help finding them with your non-goto telescope with the Push-To function. -Over 30 calculators useful for observing and astrophotography, from eyepiece magnification and field of view, to imaging resolution and reducers. -World astro-weather report based on data from 7Timer!, Dark Sky and more. -Water vapor satellite images. -List of visible ISS passes and Iridium flares. -Moon phase & lunar Calendar with solar/lunar rise/set and twilight times. -Wizard to calculate your reticle centering offset and correct or compensate for it. -Zoomable reticle view and customized routines & tools: Alt-az alignment error display for mounts that calculate it after star alignment (e.g. iOptron iEQ45, CEM60), polar alignment when your scope is not in zero position (for mounts like iOptron ZEQ/CEM on which you can always access the polar scope), remember zero position on Celestron / Skywatcher / Orion etc reticles. -Moon phase & lunar Calendar with solar/lunar rise/set and twilight times. -Approximate daytime / no polarscope polar alignment tool. Great for solar imaging (including eclipses). -Bubble level (using either gyro or accelerometer) and Compass heading, as well as magnetic declination reading. -GPS accuracy & elevation data. -Red/White/LED light. -Dimming slider. -iOptron, NexStar and Meade LX200 Star Lists. -Supports iPhone, iPad and Apple Watch.