While at home I often check wspr.net to see which low power beacons are seeing each other across the globe on the various Amateur Radio bands.
While I could look at the same website via the browser on my phone, I have come across an Android App called “WSPR World Watch” which displays the map and paths more clearly on the smart phones small screen than is possible through a browser. It also has filters you can apply, for example you can only display links that are above a certain dB level and so see which are the paths that may work with CW or set the level higher for SSB possible paths. The highest gain (lowest signal level) option will show open paths down to those that would only be possible with FT-8 or JT-65 etc. You can play around with these and other filters to customise the program to be most useful for your portable station and hence get a guide as to which band you should be trying for a particular country.
This app (which is free) could be particularly helpful in the upcoming S2S event next Saturday to see when a path from Europe to South Africa may be open on petrhaps 15m and switch there from 20m or perhaps the best chance from the UK to Canada at the time you check would be on 40 metres?
A very useful tool.
Here’s a link to it in the Google Play Store (before anyone asks, sorry, no it’s not available for iPhones).