Are there any apps or websites that show how frequently a German word is used in the spoken language and daily use ?
The type of resource you are looking for would be a frequency list or a frequency dictionary for German (in German: Frequenzwörterbuch). This type of dictionaries is created on the basis of a (text) corpus. For the spoken language, it would be necessary to record people speaking German and then transcribe the dialogues, in order to get a text corpus that can be analysed. This is a time-consuming and expensive activity, so frequency dictionaries are typically not available for free.
The Institut für Deutsche Sprache in Mannheim, Germany, provides online access to its Datenbank für Gesprochenes Deutsch, but this gives you access only to a set of corpora, not to a frequency list.
On the website of the Institut für Deutsche Sprache, you can also find DeReWo – Korpusbasierte Grund-/Wortformenlisten, but the lists available here appear to be based on written language.
The Leipzig Corpora Collection / Deutscher Wortschatz also offers lots of downloadable resources, but no frequency list for spoken German.
Instead of a website or an app, you may consider the following printed alternative: Tschirner, Erwin, Jones, Randall: A Frequency Dictionary of German: Core Vocabulary for Learners. Routledge, 2006. (190 pages; ISBN 9780415316330). The contains the 4,034 most frequently used words. According to the publisher: "Based on a 4.2 million-word corpus which is evenly divided between spoken, fiction and non-fiction texts." The dictionary is also available on Google Play: A Frequency Dictionary of German: Core Vocabulary for Learners, but not cheap.