Tip diameter is 2.4mm, so the surface area the Apex tip covers is actually 4.6mm^2, which is ~90% reduction compared to 8mm diameter stylus products on the market, which cover a surface area of ~50mm^2.
The Apex will work on the iPad 2/3/4 and the iPad Mini. Unfortunately it is not compatible with the touch screen circuitry on all capacitive devices as different manufacturers use different technologies.
We have tested the Apex with many screen protectors and found no apparent decrease in sensitivity. For the scope of this project, please note that due to the high volume of screen protectors on the market it is not feasible to run testing on the many products out on the market. As a general engineering note depending on thickness, screen protectors can affect sensitivity as it is possible for the screen protector to block electron flow and inhibit the device.
Unfortunately no. The iPhone has a different array of capacitive touch panel driver and sense lines then the iPad, and currently our TruGlide Apex has been optimized for the iPad. We continue to work on developing a more universal tuning, and hope to make it possible in future generations of the Apex stylus.
The initial prototypes were getting about 8 hours of writing time and we found we can double or triple this in the production version by pulsing the "ON" indicator LED instead of leaving it constantly on. With this, the approximate time is 20 hours, which should last an average of two weeks.
The Pro is a passive soft tipped stylus (no electronics) and it works with all touchscreens.
The Apex uses electronics to allow for a smaller tip design.
Here is a link to an independent review of the TruGlide Pro:http://forums.macrumors.com/showthread.php?t=1611770
Once the campaign is over, we will send out a survey where backers can choose to have the Pro sent to them first since it is a product already released. However, because we will be shipping out to you more than once, there will be an additional shipping fee of 3.99.
Because the Apex has electronic circuitry the packaging are more expensive than that TruGlide Pro & Artist Brush Bundle. We have also added delivery confirmation to those who back the Apex to make sure they are able to track their new product.
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