Kde has the ability to apply specific settings to a specific window or application.
If you want such behaviour for e.g. konqueror, than open it, click on the application icon (top-left), and select advanced -> special window settings or application settings (depends if you want to apply certain settings to application and all it windows or only this window you see, you can even tweak more by looking at window tab). Select e.g. special application settings and then click geometry tab, select Position and choose remember.That way konqueror will always open where you left it. You can set also dozen of other things, feel free to experiment.
You can see full list of custom settings anytime by clicking on any application icon (again, top-left) and choose: configure window behaviour -> window-specific settings. Here you can arrange list of application (delete or modify).