There are several general purpose online map tools based on Google Maps. All of us software developers do some of the same things and we also each do some unique things. It's a big world and there is room for different solutions. Different people will tend to gravitate to different tools depending on their needs.
This post is about Gmap4 - the tool that I developed. I checked in with Ryan beforehand and got the OK to post.
Gmap4 is an enhanced Google Map viewer that can display high resolution topographic maps. These maps are based on new scans that have eye-popping quality and cover the USA except for a few states that are not quite ready yet. Here’s an example showing part of the John Muir Trail in the area of Tuolumne Meadows, California.
Note that this topo map (1) is very high resolution - the paper map was scanned by the USGS at 660 pixels per inch, (2) does not have any watermarks on the map ‘tiles’ and (3) does not have any ads. At the present time, there is only one other site on the planet that is displaying these hi-res topo maps in a seamless interface.
Did I mention that you can vary the hill shading on these hi-res maps? Menu ==> Hill shading
Gmap4 also displays the medium resolution MyTopo maps and the low resolution Terraserver maps (now called Microsoft Research Maps). You can do your own quality comparison.
Gmap4 is online software that runs in your browser. There is nothing to buy, nothing to download, nothing to install. Gmap4 will run on most browsers in your phone, iPad, iPod, notebook, laptop, desktop, etc. Note that the browser does have to be online to the internet. Gmap4 is not a ‘native’ app. Instead, it is a browser app.
Q: What can you do with Gmap4 besides look at drop dead gorgeous topo maps?
A: A bunch!
I just added a trip planning feature (Menu ==> Make a map) so you can click the map to make a GPX file that you can load into many (not all) handheld GPS units. Then, when you get back from your trip you can use Gmap4 to display your GPS track.
One of the main features of Gmap4 is its ability to display data files that are hosted online almost anywhere. If you want to put your own data files online but lack your own website to host those files, then just use Google Sites. It is free, easy and it works. The Gmap4 ‘Help’ file has step-by-step instructions for uploading your files to Google Sites. Gmap4 can display GPX, KML, KMZ, TPO and Google MyPlaces files. It can also display a delimited text file format that I designed. Note that you cannot (yet) display files straight from your harddrive. You first have to put your files online.
Another key feature is the ability to share your map with others. If you click Menu ==> Show map URL, then a URL will appear in the message window. You can copy that URL and use it in a forum post, email, blog, website, etc. Whoever clicks that URL link will see the exact same map on their screen.
You can also:
* Automatically center the map on your current location (works best in mobile browsers)
* Display a UTM grid
* Get the current magnetic declination
* Get directions (the route is draggable)
* And more
There is no cost for using Gmap4 for non-commercial use. It is simply my way of ‘paying it forward’. But with that said, if you like the new high resolution topographic maps please consider making a donation (Menu ==> Donate) to help offset the hosting cost of that data. You can read more about these new topo maps in the CalTopo section of the Gmap4 ‘Help’ file.
The Gmap4 homepage has a new user FAQ, examples, a detailed pdf Help file, a links page with more examples and a bit about me.
Joseph, the Gmap4 guy